The present invention relates to a new liquid herbicidal composition, the preparation thereof, as well as the use of the composition in the control of undesired plant growth in crops of cultivated plants.
According to the present invention, a liquid herbicidal composition is proposed, which contains, in addition to customary formulation excipients, (a) at least one grass herbicide that is suspended or dissolved in a non-aqueous liquid phase, (b) at least one herbicide of the sulfonylurea type that is suspended in a non-aqueous liquid phase, and (c) at least one non-ionic or anionic, surface-active substance or a mixture of the non-ionic and anionic substances.
Grass herbicides which may be used in accordance with the invention belong especially to the chemical classes of acetanilides, phenoxypropionic acids, pyrimidinyloxybenzoic acids, phenylsulfonyltriazoles, oxyacetamides, oxazolidindiones, phenylbenzamides, pyrimidinyl thiophthalides and indanes, and are preferably pretilachlor, cyhalofop, pyriminobac, cafenstrole, mefenacet, fentrazamid, oxaziclomefon, pentoxazone, etobenzanid, indanofan as well as epoprodan and the compound of formula I 
These grass herbicides may also be used in a mixture together. They exist in dissolved or dispersed form in a non-aqueous liquid phase. The herbicides of the sulfonylurea type are also dispersed in preferably the same non-aqueous liquid phase. These are preferably cinosulfuron, pyrazosulfuron, bensulfuron, azimsulfuron, imazosulfuron, ethoxysulfuron, cyclosulfamuron or halosulfuron or mixtures thereof.
The preferred non-aqueous liquid phases include all vegetable and mineral oils, such as rapeseed oil, soybean oil, sunflower oil, castor oil, pine oil, cottonseed oil, as well as derivatives of these oils, for example esters, especially methylesters of these oils, as well as paraffinic and aromatic mineral oils, such as Orchex 796, Shellsol types, Isopar types, aromatic fractions, such as Solvesso 200 and esters such as Exxate 700, as well as mixtures thereof.
The non-ionic and anionic surface-active substances may be conventional, commercially available substances, for example ethoxylated vegetable oils such as Emulsogen EL, ethoxylated fat alcohols such as Genapol O-050, ethoxylated alkylphenols such as Synperonic NP8, ethoxylated polyethylene glycols or polypropylene glycols, e.g. Pluronic types, ethoxylated tristyrylphenol derivatives such as Soprophor 4D384 or Soprophor S/25, oleyl polyglycol ethers such as Genapol U-050, and silicone surfactants such as Silwet L77, as well as dodecylbenzene sulfonates such as Sermul 88A, alcohol ether sulfonates such as Genapol LRO, lignin sulfonates such as Ultrazin NA, phenol sulfonates such as Sipragil GN and polycarboxylates such as Geropon TA72, sulfonated naphthalene/formaldehyde condensates such as Supragil MSN, sulfosuccinates such as Aerosol OT 70 PG, polyacrylate derivatives such as Atlox 4913, maleic acid/olefin copolymers such as Sokolan CP9, alkyl polyglycosides, alkyl succinic acid anhydride derivatives, sorbitan esters, ethoxylated sorbitan esters, alkyl and alkylaryl polyglycol ether phosphoric acid esters and ethoxylated fatty acid esters, as well as taurides such as Hostapon T hk.
The above-mentioned herbicides are described in the Pesticide Manual, Eleventh Edition, British Crop Protection Council, 1997. The compound of formula I is known from EP-A-447506, fentrazamid from British Crop Protection Conference Proceedings, 1997, 67-72, and oxaziclomefon from British Crop Protection Conference Proceedings, 1997, 73-80.
Preferred herbicidal compositions according to the present invention contain as the grass herbicide cyhalofop, pyriminobac, cafenstrole, mefenacet, fentrazamid, oxaziclomefon, pentoxazone, etobenzanid, indanofan, epoprodan, pretilachlor or a compound of formula I 
or mixtures thereof.
As the herbicide of the sulfonylurea type, the compositions according to the invention preferably contain pyrazosulfuron, bensulfuron, azimsulfuron, imazosulfuron, ethoxysulfuron, cyclosulfamuron, halosulfuron or cinosulfuron or mixtures thereof.
The non-aqueous liquid phases to be used are preferably mineral oils or vegetable oils, or also mixtures thereof. The preferred non-ionic, surface-active substances that may be considered are ethoxylated vegetable oil, ethoxylated fat alcohol, ethoxylated alkylphenol, ethoxylated polyethylene glycol and polypropylene glycol and copolymers thereof, ethoxylated tristyrylphenol derivative, oleyl polyglycol ether or silicone surfactant, and the anionic surface-active substance may be a dodecylbenzene sulfonate, sulfosuccinate, ethoxylated tristyrylphenol sulfate or phosphate, alcohol ether sulfonate, lignin sulfonate, ethoxylated phenol sulfonate or polycarboxylate.
A significant composition is one which contains as the grass herbicide pretilachlor or the compound of formula I or a mixture thereof suspended or dissolved in a vegetable oil, as the herbicide of the sulfonylurea type bensulfuron, pyrazosulfuron, azimsulfuron, imazosulfuron or cinosulfuron or mixtures thereof suspended in a vegetable oil, and as the surface-active substance a mixture of non-ionic and anionic compounds. Of these, preference is given to a composition which contains as the grass herbicide the compound of formula I suspended or dissolved in a vegetable oil, as the herbicide of the sulfonylurea type cinosulfuron suspended in a vegetable oil, and as the surface-active substance a mixture of non-ionic and anionic compounds. Of these, further preference is given to a composition which contains as the grass herbicide pretilachlor suspended or dissolved in a vegetable oil, as the herbicide of the sulfonylurea type cinosulfuron suspended in a vegetable oil, and as the surface-active substance a mixture of non-ionic and anionic compounds.
An especially effective composition contains as the grass herbicide pretilachlor or the compound of formula I or a mixture thereof, preferably the compound of formula I alone, suspended or dissolved in rapeseed oil or rapeseed oil methyl ester or in a mixture thereof, as the herbicide of the sulfonylurea type bensulfuron suspended in rapeseed oil or rapeseed oil methyl ester or in a mixture thereof, and as the surface-active substance a mixture of a non-ionic with an anionic compound selected from castor oil ethoxylate, dodecylbenzene sulfonate, ethoxylated tristyrylphenol sulfate and oleyl polyglycol ether.
The compositions according to the invention have the great advantage that they may contain the herbicidal active ingredients in high concentrations, and that they remain protected from decomposition over a longer period of time. They also offer the possibility that other oil-soluble or liquid admixtures may be added without problems, such as additives that are suitable for increasing the biological activity, as well as stabilisers such as epoxidised vegetable oils. Surprisingly, the compositions according to the invention show practically no damage to the crops of cultivated plants after their application, despite using organic liquids.
The compositions according to the invention are preferably suitable for the control of weeds in flooded paddy fields. The process is advantageously carried out in such a way that the required amount of composition is mixed with the same amount or up to ten times the amount of water, and applied directly to the already flooded paddy field, or is added to the water flowing in during flooding of the paddy field (so-called splash application). Furthermore, it is also possible, to apply the composition dropwise or in portions simultaneously with the mechanical planting of the rice plants (so-called dip application). Spray application of the composition according to the invention is similarly possible, but requires a higher dilution with water.
The application rates of composition according to the invention may vary within a wide range. It is preferable to use 50 to 2000 g/ha herbicide (grass herbicide plus herbicide of the sulfonylurea type).
The liquid compositions according to the invention contain per liter preferably 30 to 1920 g grass herbicide and 20 to 80 g herbicide of the sulfonylurea type, as well as 50 to 300 g of surface-active substance (anionic plus non-ionic). Normally, 2-20 I/ha of the formulations described below by way of example are required for direct application or for splash application. For spray application, this amount is usually 20-500 I/ha. The compositions according to the invention may also contain further customary additives, for example inert carriers such as kaolin and chalk, stabilisers, anti-foaming agents, preservatives, viscosity regulators, thickeners such as silicic acid or bentonite, binders, tackifiers, as well as fertilisers or other active ingredients. The compositions are produced in known manner, e.g. by intimately mixing and/or grinding the active ingredients with the formulation excipients and with liquid or solid carriers. Particularly preferred formulations are made up as follows: